3/4 OSB flooring, Moisture barrier also?

[TxPowderCoater]

I have a 20x20 woodframed shop in the country we are finishing, doing the 3/4" T&G OSB flooring and was curious, should I do a moisture barrier?
the shop is on blocks so a little airflow under will help, but should I staple a couple layers of 6 mil plastic down and then the flooring or maybe 30# felt in strips?
Do I not need a moisture barrier and just place plastic shiny side down?
I plan of doing the top in oil base kilz and then maybe put some tile down, I dunno.
Thanks in advance

 

[DekeT]

I would use treated plywood for that floor.

 

[TxPowderCoater]

I would use treated plywood for that floor.

thats not at all what I asked....thnx anyways.

 

[DekeT]

thats not at all what I asked....thnx anyways.

Well its not clear if you are doing subfloor and then tile over that. It also sounded like you are putting osb facing the ground. If that is wrong just ignore me.

 

[pattenp]

If your shop has a crawl space between the floor system and earth then the moisture barrier such as plastic lays directly on the earth. If we're talking vapor barrier as if the floor is to be insulated then the plastic goes to the under side of the floor sheathing between the insulation and the floor. It's good to have both. If your shop is on block piers and is open all the way around then you may forgo the moisture barrier on earth.

 

[TonyF]

Well, Im no pro but on mobile homes there is usually at least a foot of clearance between the ground and home, a vapor barrier, insulation and then the OSB floor.


I would go with the vapor barrier. It is relatively cheap anyway

 

[TxPowderCoater]

thanks for all the answers.
was picturing the condensation gathering underside of the floor in droplets and was worried about it. With the air space, I wasnt sure if it would accumulate or not.
The osb is going to be put on 2x6 joists and I was curious if I should barrier under it (OSB) or not.
If I do a plastic barrier over the 2x6's and under the OSB then I should be able to put the shiny, smoother side up.
I was planning on painting the floor surface for sealing and maybe do a tile floor over it.

 

[thegarageguy]

What you can do is staple some roofing paper, and metal lath on top. Typically 25 staples pr square foot. Then you can pour an Ardex type acrylic modified concrete. You can then seal it with a water based acrylic sealer to keep it dust free for you. I attached some progress pics to give you an idea

 

[TxPowderCoater]

^^^ damn, that cool indeed.

 

[964haus]

^^^ damn, that cool indeed.

The garage guy,
I was thinking of using this sort of product on a shed I'm planning on building - it's a 10x16 shed on concrete piers (so off ground) and I'm looking for a hardy flooring option. Do you have any examples of this used in a shed? What's the durability like?

Thanks!
matthew.

 

[thegarageguy]

Never done a shed but that being said, it shouldn't be a problem if you are looking for a concrete look. The only possible issues would be if you have too much vertical movement or if the floor isn't sturdy. This could cause the concrete to hairline excessively.

 

[slickgt1]

I am a bit confused.

I have a 20x20 woodframed shop in the country we are finishing, doing the 3/4" T&G OSB flooring and was curious, should I do a moisture barrier?

If you are doing T&G flooring, then yes, put 30# felt under, and nail flooring through it.

the shop is on blocks so a little airflow under will help, but should I staple a couple layers of 6 mil plastic down and then the flooring or maybe 30# felt in strips?
Do I not need a moisture barrier and just place plastic shiny side down?


I plan of doing the top in oil base kilz and then maybe put some tile down, I dunno.

You going to cover the flooring in Killz?

If you are going for tile, do it right the first time. Put down cement board. Durok for example. Glue and screw it. Then tile over that.